1. Field of the Invention
The invention relates to the field of pet care and, more particularly, to a self-cleaning litter box for waste disposal.
2. Description of the Related Art
Various designs have been proposed for litter boxes having devices to make cleaning the litter in the box easier. These devices typically involve sifting screens which remove feces from litter when the litter is sifted through the screens.
For example, U.S. Pat. No. 3,141,44 to Russell discloses a litter box having two containers, one of which has a grating in the bottom, and a solid sheet which lies over the grating. When it is time to clean the box, the solid sheet is removed and the box with the grating is lifted out of the solid box. The litter sifts through the grating and into the solid-bottom box, while the feces remains in the box with the grating, and is then discarded. The solid sheet is then replaced in the grated box and the litter is poured back in this box for re-use.
This box allows the litter to be sifted. This sifting, however, requires multiple lifting of the box with the litter, a task which may not be easy for the elderly or infirm pet keeper. Also, the feces must be discarded after each use of the sifter, and the sifting process can result in spillage of the litter unless the boxes are kept in alignment.
U.S. Pat. No. 3,482,546 to Anderson discloses a litter box having a tilting screen in the bottom. When it is time to clean the box, the screen is lifted through the litter and waste materials are caught by the screen and collected in the tray.
This device also allows the removal of feces from litter, but again requires that the feces be disposed of after each cleaning of the litter box. Further, during use of the device, litter as well as feces will be discharged through the opening of the litter box. Also, difficulty is encountered when replacing the grating for use, as the grating must be forced back into position through the litter.
U.S. Pat. No. 4,096,827 to Cotter discloses a litter box which is structured like a briefcase and has two portions with a screen disposed therebetween. In use, the device is opened and one side lies flat on the floor. The other side remains vertical and is not used. When it is time to clean the box, the non-used side is closed over the used side and the box is inverted. The litter passes through the screen, and feces are caught and maintained in the first side. The box is then opened in an upside down position to the original position and the feces may be removed.
This device also provides effective sifting of litter, but still involves lifting of the entire litter box to effect the sifting, and feces must be disposed of after each sifting.
U.S. Pat. No. 4,886,014 to Sheriff discloses a pet litter box having two semi-circular swelled out chutes and a wire mesh separator. While this device also appears to provide effective sifting of waste material, its operation requires a lifting of the entire box and at least 5 steps to operate, as follows: 1) lifting and tilting the box to collect litter in the side chute; 2) tilting the box to transfer the collected litter to the end chute; 3) lowering the box so that the collected litter is sifted through the wire mesh; 4) tilting the box to empty waste material from the wire mesh; and 5) setting the box flat while redistributing the litter for further use.
Other patents which disclose sifting type litter boxes include U.S. Pat. No. 2,713,321 to Keen; U.S. Pat. No. 3,233,588 to Thomas; U.S. Pat. No. 4,190,525 to Menzel; U.S. Pat. No. 4,802,442 to Wilson; U.S. Pat. No. 4,817,560 to Prince et al.; and U.S. Pat. No. 4,846,103 to Pierson, Jr.
All of the above devices require intricate procedures to effect the screening of the litter. It is, therefore, desirable to provide a litter box wherein the cleaning procedure is simple.
An additional shortcoming of the above-described known devices is their inability to provide an easy manner of disposal of the litter when it is used to the point where the litter must also be discarded and replaced.
Thus, the objects of the present invention include:
1. providing a litter box which can be operated in a simple procedure without excessive lifting or shaking of the litter box;
2. providing a receptacle for the litter box which catches and stores sifted feces in a substantially airtight container;
3. providing a litter box capable of easily redistributing the litter for additional use after it is sifted;
4. providing a litter box which allows easy and sanitary disposal of the feces as well as the litter when it is no longer usable.